THE SPRAY NOZZLE:
The spray nozzle transforms the energy of a liquid into kinetic energy. The later is utilized to break the liquid into small particles and to disperse them evenly according to the desired pattern. In some cases the kinetic energy is used to give higher penetration force to the spray. The combination of the nozzle type, nozzle size, and liquid pressure, determines the flow. As you increase pressure you increase flow-rate/capacity. Tables are located throughout the catalog to help you determine the flow rate of each nozzle at varying pressures.
In general the relationship between the flow and liquid pressure is the following:
Q1 and P1 are known capacity and pressure. Q2 is the resulting flow at desired pressure P2. All the tables of the catalog are based on water.
There are several different nozzle designs and patterns. The ideal type and pattern to use will vary according to the application. The four basic spray patterns are:
Hollow cone spray: type A
A round pattern with the spray concentrated on the outer rim of the pattern. The interior of the pattern has no droplets, which makes it a hollow cone. The impact area of the hollow cone pattern is cylindrical.
Full cone spray: type B
A round spray pattern that is filled with liquid droplets.. The impact area of the full cone pattern is circular, with a relatively even distribution of the droplets throughout.
Flat jet: type C
A flat pattern is primarily linear. Different nozzle types can produce different types of flat spray patterns, which can vary from purely linear to more elliptical in shape.
Atomizing nozzle: type E
In air atomizing nozzles compressed air is mixed with a liquid stream to create fine atomization. In hydraulic atomizing nozzles the atomized spray is created through hydraulic pressure, compressed air is not needed. From the tables in the catalog you can choose the type of atomizer that best suits your specific requirements.
The spray angle is usually measured near the orifice. As you increase the spray distance , the measurement of the spray becomes less exact. Additionally, an increase in the viscosity of the liquid will reduce the spray angle. The table lists the theoretical coverages at various distances based on the spray angle. All measurements are based on spraying water.
Droplet size (atomization)
The major factors affecting droplet size are the capacity, the liquid pressure, the spray pattern, and the nozzle type. Usually an increase in the flow, under the same liquid pressure, produces larger droplet sizes. An increase in liquid pressure reduces droplet size, while increasing the spray angle in most nozzle types. Air atomizing nozzles produce the smallest droplet sizes, full cone nozzles produce the largest droplet sizes. For every spray pattern, the table shows the median droplet sizes relative to the minimum and maximum flow (capacity) values, at a liquid pressure of 3 bar or 45 psi.
The spray impact depends on the capacity, pressure, spray pattern, and nozzle type. The highest impact is produced by solid stream and flat spray nozzles, the lowest impact would be wide angle full cones. Hollow cones can have higher impact on the outer rim and are often used for impingement in metal cleaning and surface treatment applications.
Nozzle wear can vary greatly based on the nozzle type, nozzle material, liquid pressure, and liquid quality. Typically, stainless nozzles will have a wear life 3 to 5 times that of brass. High pressure, as well as liquids that contain abrasives or solids, will wear nozzles at an accelerated rate.
Classification of spray measures
The standard material for our products are indicated in table 1. Amerispray may offer alternative materials for certain nozzle types, other than what is listed in the catalog. Please inquire with our sales representatives for alternative materials.
SPRAY NOZZLES identification method
– the first position identifies the material (see table 1)
– the second position identifies the connection size ( table 2)
– the third position identifies the model of the nozzle; locate the nozzle type in the catalog to determine the model type.
– the fourth and the fifth positions identify the flow and spray angle of the nozzle ( for example C2 flat spray)
Example: to order a nozzle in brass, with a male 1/8” thread, C2-03/110°,the part number would be: O0MC203A. See the material reference table below.
The material for high pressure nozzles MC4-C4 and HP is not listed, so the article code starts with the thread or the model (Example: C4-020 – 1HP022)
* Only for flat sprays
Below is an example of how to order a flat spray on page 34 (MC2 MODEL) 1/8-MC2-03/110°- (Brass)